By using of the second quantization method [1]}, [2]}, [3]}, from the equation (REF ) spring that the field operator \(\mathbf {\Phi }[h]\)  of the reduced equation (REF ) can be represent in the Fock space of annihilation and creation functional operators
\(\mathbf {\Phi }[h]=\mathbb {Q}[h]\mathfrak {B}[h],\) 
